The use of jumper cables for starting the engine of a vehicle having a weak or dead battery is well known. The basic jumper cable unit comprises a pair of cables having connector means at the ends thereof for attachment of the cables to the terminals of a pair of batteries, one of which is "dead." Such cables are connected directly to the battery terminals and there are no safety features associated with such cables to protect against bodily injury to the user of the cables.
When jumper cables are directly connected to the battery terminals of a pair of batteries, there have been instances in which bodily injury has occurred. In some cases, batteries have exploded because of the presence of combustible gases which are ignited when a spark is generated as one end of a cable is connected to a terminal of a live battery. As a result of such problems, safety circuitry has been included as part of a jumper cable assembly. Such circuitry is generally complex in construction and expensive to produce. As a result, such battery cable assemblies have been found unacceptable by the general purchasing public. Disclosures directed to jumper cables having safety circuits associated with them are found in the following U.S. Pat Nos.: 4,163,134, 4,166,241, 4,180,746, 4,217,534, 4,238,722, 4,272,142, 4,349,774, 4,366,430, 4,420,212, 4,463,402 and 4,488,147.
Because of the dangers of using jumper cables without safety circuitry and because jumper cables used with such safety circuitry are complex in construction and expensive to produce, a need exists for a jumper cable assembly which is simple and rugged in construction, can be used by persons with no special skills yet the assembly provides safety features against bodily injury and damage to batteries with which the assembly is to be coupled. The present invention satisfies this need.